Method of forming edible dust-free particles



United States Patent G F METHOD OF FORMING EDIBLE DUST-FREE PARTICLESPaul Bonnafoux, Lancaster, Calif.

No Drawing. Application September 2, 1954, Serial No. 453,951

4 Claims. (Cl. 99-2) This invention relates to a method of formingdustfree particles of edible material, said particles being generallyknown to the trade as crumbles.

One of the major problems encountered in the manufacture of varioustypes of poultry and animal feeds is the problem of edible dusts formedduring the processing of said feeds. For instance, a common form ofpoultry or small mammal feed is that sold in crumble form whereinparticles of the feed varying in size from about 5 to 7 of an inch areprovided. When these particles are fabricated by customary procedures,large quantities of dust are formed which are separated from thecrumbles by screening. Since the dust frequently constitutes as high asfifteen percent of the total output, it must be rerun through theprocess which lowers the food value of the edible material and alsoreduces the output of crumbles.

Crumbles or particles of feed are usually formed by grinding the feedafter it has been pelletized subsequently to the cooling of the pellets.As a matter of fact, most grinding of the pellets takes place arelatively long time after the formation and cooling of the pellets.When the hardened pellets are ground, edible dusts inevitable formsince, during the grinding process, pulverization of certain parts ofthe pellets, due to attrition, necessarily takes place.

It is, therefore, an object of myinvention to provide a method offorming dust-free particles of edible material known to the art ascrumbles, thus eliminating the annoyance and loss occasioned by largequantities of edible dust resulting from the formation of crumbles byconventional methods.

In describing the steps of my method, I will illustrate said steps bythe application of the method to the formation of crumbles of alfalfabut it is, of course, not intended that the method of the invention belimited to this specific application since poultry and other feedsmanufactured from variousmixtures of cereals or other ingredients can bereadily formed into dust-free particles by the application of theteachings of my invention.

Another of the disadvantages of the conventional methods utilized informing crumbles for feed purposes is the fact that, when the pellets offeed are formed by extrusion under the tremendous pressures necessary,the heat generated in the process results in elevated temperatures inthe pellets and the pellets must necessarily be cooled to reduce saidtemperatures and the oxidation of the edible elements included in thepellets so that the vitamin content and color of the pellets will not beadversely affected. Because of the exceedingly compact nature of thepellets, the cooling process frequently takes as long as twenty minutesand during this process the oxidation of the edible components of thepellets takes place, reducing the vitamin content and altering thenatural color thereof. Therefore, when crumbles are formed from thepellets by grinding the same after they have cooled and hardened, theresulting particles are not only accompanied by a substantial amount of2,786,760 Patented Mar. 26, 1957 ice edible dust, but the vitamincontent thereof has been lowered and the natural color of theingredients substantially darkened by the oxidation resulting from theprolonged heating period.

An additional object of my invention is the provision of a method offorming dust-free particles of edible material which includes the stepsof forming the edible material into homogeneous, solid bodies whichmomentarily retain their semi-plastic nature after their formation and,immediately thereafter, grinding the semi-plastic bodies into particleswhich are characterized by the substantially complete absence of edibledust.

A further object of my inventionis the provision of a method of theaforementioned character wherein the edible material is ground andmoistened prior to the formation of the aforesaid bodies and wherein theaforesaid bodies are formed by the extrusion process, the high pressuresoccasioned by said extrusion process resulting in the elevation of thetemperature of the ground edible material to temperatures in the rangeof 210 F. Of course, the elevated temperatures reached during theextrusion of the bodies materially increases the plasticity of theedible material and results in a homogeneous, extremely compact pelletwhich is discharged from the extruding device in semi-plastic, heatedcondition. While the pellet still remains in the semi-plastic, heatedcondition, it is subjected to a grinding process which results indust-free particles of edible material or crumbles.

In the formation of alfalfa crumbles, the basic raw material consists ofalfalfa hay and this hay must be moistened subsequently to the grindingthereof prior to the formation of semi-plastic bodies from the groundhay. In order to assist in the agglomeration of the ground hay, it ismoistened by steam which necessitates the provision of a boiler or othersteam-generating apparatus in the plant where the crumbles are formed.

Another object of my invention is the provision of a method of formingalfalfa crumbles which includes the step of admixing with the alfalfahay freshly mowed alfalfa bearing its full content of natural moisture.When the alfalfa hay and the freshly mowed alfalfa, in green form, areground together, the natural moisture of the green alfalfa eliminatesthe necessity for moistening with the steam in the above describedconventional manner and eliminates the necessity for the maintenance ofa steam plant.

In addition, the natural green of the fresh alfalfa materially improvesthe color of the end product and, of course, increases the vitamincontent of said end product.

As previously indicated, I will illustrate the method of my invention asapplied to the formation of alfalfa crumbles, but it is, of course, notintended to limit the application of the principles of my invention tothe specific product since it is obvious that various types of animaland other feeds may be formed into dustfree crumbles by the utilizationof the teachings of my invention.

As the first step of the process, the dry alfalfa hay is ground in ahammer mill, or similar device, to reduce it to relatively smallfragments. Subsequently to the grinding of the hay, it is moistened, asby means I of steam, to facilitate the agglomeration of the ground hayduring the formation of individual bodies, or pellets, therefrom.

After the moistening of the ground hay has taken place, the ground hayis subjected to a forming process wherein it may be formed eitherintoindividual compacted pellets, or into continuous extruded lengths ofedible material which are equivalent in density and plasticity to thedensity and plasticity of the aforementioned pellets.

For instance, one conventional method utilized in forming the extrudedlengths of edible material is to feed the moistened, ground hay betweentwo rolls which areprovided with a plurality of radial openings throughwhich the ground ahd'moistened hay is forced. 'Since 'pressuresaslhighas 10,990 s. ifaie exerted upon the ground hay du'r-ing theextrusionprocess, relatively high temperatures are engendered in the hay whichare conducive to greater plasticity in the ground hay and .mate- 'riallyfacilitate formation of the ground hay into compact bodies or pellets.

' 'lhave attempted to ascertain-the temperatures at which the ground hayis extruded from the extrusio 1 machine and have found ther'nf t o rangebetween 125 F. and 210 F, the range in temperature being attributable tothe density of thehayfmix, itheextentt o which the hay hasbeenmoistened, andthe speed at warmth; formi l g dies are rotatedftogetherwith the pressure exerted upon the g'roundhaybysaid forming dies. 7

""The ground hay forrnedintolcompact, solid, elongated Bodies which,because of the intense heat and pressures to which hav e lb een subected, are semi -plastic in inatiure and atlter npe ratures rangingbetween l 25 F. and 219 F: :they is siie frorn the extruding machine. iscustomary practice, the elongated bodiesare cut into pellc ts andaresubsequently cooled by being passed through a blast of cooling air whichresults in tlie'reductionlof. the temperaturelof the pellets to theambient temperat ire approximately twenty minutes. However, during thiscooling period large percentage of the nui i 'l a re a d P rti l ly ami.A s lost. conventional practice, after the pellets have been cooled,they are then ground and formed into particles ranging insize from to Aof laninch, withrare exceptions, 1. provide thi aieaa se d t h a ena eso During the conventional process, a large amount of ,edi-

dust, approximately fifteen percent, is formed and since the c'runibles'are screened, this edible dust is rejected and bereprocessedrthroughthe forming dies of the extruding machine. Naturally, such reprocessingentails a considerable loss in handling and machine time and,furthermore, reduces the nutritional content of the reprocessedediblemateriallbec ause of the fact thatiit is tl vitxe or three timessubjected to intense pressures and heat. y "Y u In the process of myinvention, when the elongated extruded bodies issue from the lextru dingdevice, they are immediatelylyvhile in semi-plastic and heatedcondition, passed to grinders which break" the elongated bodies intoparticles. Becauseof the semi-plastic nature of the bodies and thetendency of the constituent edible material thereof to remain inaggIOmeratejclfo rm, there is complete absenceof the edibledustencountered when the crumbles are formed by conventional processes.Furthermore, smegma bodies are immediately'rednced to particlesiz'efjthe oooling of the particles ,is expedited .With theiresulf that.the food values of the CIlllljlblCS 'areipreser vedsince there is notencountered the long coolperiod necessary when the material isretained'in pellet form as is the case in conventional practice. Thus,wi the mac o m inv n i here i n ne ess y for reprocessing .a .relativelylarge amount 0? dible dust and the hu tritional values of the ediblematerial being processed are retained at a high level because of thefact that the immediate reduction of the bodies of material to crumbles,causes and permits the quicker cooling thereof. Y After the elongatedbodies have been formed into crumbles they are passed through a cpolingblast of air to accelerate .the cooling process. Subsequently, they arescreened to remove any excessively large particles from the mass and therelatively few exc essiyely la'rge encountered in conventional'practiceare regronn'd.

As previously indicated, it is necessary to moisten the :dried groundmaterial with. steam or other moisture in order to permit and facilitatethe agglomeration of the edible material. Moistening the edible materialby the use of steam necessitates maintenance of a steam generat 'TtlOl1dalfalfa hay, it is; dumped on, a. conveyor line and green, fresh alfalfais dumped on top of the hay in a per- 'centage ranging from ten totwenty-five percent. The mass of green alfalfa and alfalfa hay isthenfedtothe .hamm e'rjmillor other grinding machine and [the en;ti rerm ass is thoroughly ground and mixed to disperse the :fresh, moist,green alfalfa among-thealfalfa hay.

I Thus-the moisture content of themix isautomatically tincreased withoutthe necessity 'fOI: t h use gf additional -moistening means such assteam, previouslyjnen'tiqne a lbeing customarily used. Furthermore,since the fresh, green color of the alfalfa is; imparted to theihay, theoolor of -the end product islm agterially improved. Inaddition, thevitamin contentand particularly the vitamin .A con- :tent of .the endproduct is raised to a substantialextent.

I, therefore, provide a method for forming icrnmfles -of ediblematerialwhich results inia product characiteriz ed by the absence of thelarge quantities of dust resulting .fromconventional processes andwhichalso resnltsin a ;superior, better color, more nutritious produ ct.

I claim as my invention: 7'

n e i of forming qs z rs .parti le nfnnultry rand animal edible feedmaterial, the steps ofgs'irnnltaneouslyisubjecting said edible materialt o'heat andp essure;

rextr'uding said edible material into elongatedbodiesin a semi-plastic,heated state; and grinding said elongated :b'odies' while still ins'aidsemi-plastic, heated state to Lform .dust-free particles of saidediblematerial.

--2. -In a method of forming dust-free particles of poultry rand animaledible feed material, the steps of; subjecting :said edible "materialsimultaneously to heat andpressure;

extruding said edible material in the form of semi-plastic,vpellets;"grinding said pellets while still hot and in said semi-plasticconditionto form dust-free particles of said edible material; andcooling said dust-free particles to prevent oxidation of said ediblematerial.

3. In a method of forming dust-freeparticles from ground poultry and,animal edible feed material the steps of: moisteniiig said ground ediblematerial to facilitate -the agglomer ation of the same; subjecting saidrno istened ediblematerial to pressure said pressure eansing the heatingof said'mois'tened ground .rnateri al; rig said edible m i l n o ftmi-Rles i lis lets; an r a i P l W ii a d.hea ed rem -nl s i state toformsaid dust frete particles u I L H 49111 a h 9 qmmaduskfm n esf oground poultry and animalediole feedmaiterial the steps of:sirriultaneously subjecting said ground material -to heat within a rangeof F. to 2lll F. and pressure to: extrud'e homogeneous, solid pelletstherefrom which are momentarily in a semi-plastic and heated state; andgrinding said solid pellets while still in said semi-plastic 'and heatedstate to form said dust-free particles.

.lia srenss gtrdtathefils patent

1. IN A METHOD OF FORMING DUST-FREE PARTICLES OF POULTRY AND ANIMALEDIBLE FEED MATERAIL, THE STEPS OF: SIMULTANE OUSLY SUBJECTING SAIDEDIBLE MATERIAL TO HEAT AND PRESSURE; EXTRUDING SAID EDIBLE MATERIALINTO ELONGATED BODIES IN A SEMI-PLASTIC, HEATED STATE; AND GRINDING SAIDELONGATED BODIES WHILE STILL IN SAID SEMI-PLASTIC, HEATED STATE TO FORMDUST-FREE PARTICLES OF SAID EDIBLE MATERIAL.